MV & HV Cold Shrink | Cable Accessory Failure Modes

Published 08 Mar 2021

MV & HV cold Shrink

What is Cold Shrink for Medium and High Voltage Cables?

Developed in the 1970’s by 3M, MV & HV Cold Shrink technology has been found to be safer, more reliable and easier to install for the jointing, terminating and abandoning of power cables.

3M Cold Shrink is made from either EPDM (Ethylene-Propylene-Diene-Monomer) or silicone rubber, that is expanded onto a spiral core. After the cold shrink tube has been placed over the joint or cable termination end, this inner spiral is pulled out. The insulating tube then contracts to its pre-stretched size and shrinks onto the cable, exerting constant radial pressure for the lifetime of the joint or termination.

Cold Shrink Offers the Maximum Mechanical Protection

Cold shrink products have a 45+ year track record of performing exceptionally well in indoor and outdoor environments, including under harsh conditions.

The silicone material conforms well to cable bends, which ensures long term reliability against moisture ingress, or voids within the installation. It is shows excellent performance in the following environments:

Refineries
Coastal environments
Altitude
Dusty environments eg. solar power plants, wind farms
Vibrations eg. railroad, subway
Underwater environments
Overhead joint applications

Cold shrink

Cable Accessory Reliability

There are a variety of issues that can impact on the reliability of MV & HV cable accessories.

These issues include:

Improper Accessory Selection
Difficult to Follow Instructions
Workmanship
Number of Installation Steps
How the Accessory is Delivered to the Cable
Materials Used to Manufacture the Accessory
Tolerances & Product Design
Environment Factors
Training & Support

Medium Voltage cable accessories

3M Electrical manufacture a range of cable accessories for medium and high voltage cables, including cold shrink, which enable quick and easy installation and efficient operation.

Terminations	Separable Connectors	Joints / Splices

3M™ Cold Shrink QT II and QT III Indoor and Outdoor (skirted)	200 Amp Load Break Elbows	3M™ Cold Shrink QS III Cable Splice Kits
	600 Amp Dead Break T bodies	3M™ Cold Shrink QS4 Integrated Splice Kits
Cold shrink enables quick and easy installation QT III is a true one piece termination > eliminates extra manual steps, including greasing and taping, helping to avoid human error and reduces labour time	Meets IEEE 386 standard Allows connections to be easily plugged and unplugged	Broad product line Cold shrink enables quick and easy installation Available with shear bolt connectors which eliminates need for crimping equipment and dies

Further Reading

3M – DISTRIBUTORS, STOCKISTS & SUPPLIERS

Thorne & Derrick provide competitive prices and fast delivery from stock for the complete range of 3M Scotchcast and Cold Shrink cable joints, terminations, resins and Scotch electrical tapes – we stock high voltage cable joints and terminations manufactured from 3M using Cold Shrink for 11kV and 33kV cables.

Thorne & Derrick

Thorne Derrick 35

LV, MV & HV Jointing, Earthing, Substation & Electrical Eqpt

Thorne & Derrick International are specialist distributors of LV, MV & HV Cable Installation, Jointing, Duct Sealing, Substation & Electrical Equipment – servicing UK and global businesses involved in cable installations, cable jointing, substation, overhead line and electrical construction at LV, 11kV, 33kV and EHV.